Scientists Warn of New Methane Leaks in Antarctic Seafloor

Scientists have discovered new methane seeps beneath Antarctica’s ice in the Ross Sea region, likely linked to climate change.

“We establish the recent emergence of many of these seep features, based on their discovery in areas routinely surveyed for decades with no previous seep presence,” write the researchers behind a recent study published in the journal Nature Communications.

The discoveries suggest that Antarctic seafloor seeps are not rare but widespread, raising questions about what’s driving their emergence.

The scientists say the origin and mechanisms of the new seep systems remain uncertain, but similar processes can be seen in paleo-records, where they are linked to past periods of climate-driven changes in the cryosphere—a term used to refer to “the Earth’s ice in all its forms,” predominantly in the Arctic and Antarctic regions. Finding these leaks now indicates a strong likelihood that they are linked to the current period of human-caused climate change.

Methane itself is a powerful greenhouse gas that traps more heat than carbon dioxide, though it remains in the atmosphere for a shorter time. If areas with leaking methane are widespread around the Antarctic, there may be “concerning positive feedbacks that are currently undetermined,” the researchers warn. Some short-term impacts may also be seen in ecosystems local to the leak sites.

While a specific cause of the methane leaks was not determined as part of the study, researchers suggested that other leakages have been indirectly connected to melting ice sheets. As atmospheric temperatures rise, the ice sheets melt and lose mass, which in turn reduces the weight they impose on the Earth’s surface beneath them. The change in pressure affects methane locked in reservoirs under the ice and allows it to escape. “Subglacial recharge”—when water enters the reservoir—can also transport more methane out of the reservoir to escape.

The researchers emphasized that much about the leaking methane, and the processes driving it, is unknown. But methane’s important role in global warming and the ongoing climate impacts affecting polar regions make the topic a global research priority.

“Whether this is indicative of ongoing climate impacts in the region, as has occurred in the geologic record and in the Arctic, or a regime shift with local impacts on the ecology of the region, should be a focus of research in both the Ross Sea and Antarctica,” say the researchers, who “recommend coordinated, international research efforts to address this important topic.”